Book digitized by Google and uploaded to the Internet Archive by user tpb.
Notes
The first of the four treatises (1797) was originally published in Helmstädt, 1799, as an inaugural dissertation. The second (1815) and third (1816) appeared in the Commentationes recentiores of the K. Gesellschaft der Wissenschaften zu Göttingen,III, 1816. The fourth (1849) was published in the Abhandlungen of the same society,IV, 1850.